Receivables from customers and notes receivable, net Level 4 - Allowance for Bad Debts Rollforward (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended		9 Months Ended
	Jun. 30, 2012	Jun. 30, 2011	Jun. 30, 2012	Jun. 30, 2011
Allowance for Doubtful Accounts Receivable [Roll Forward]
Allowance for Doubtful Accounts - Customer and Notes Receivable			$ 11.9
Provision for Doubtful Accounts		3.0	0.5	7.5
Allowance for Doubtful Accounts Receivable, Charge-offs			(9.5)
Allowance for Doubtful Accounts Receivable, Recoveries	1.8	1.8	0	3.7
Allowance for Doubtful Accounts - Customer and Notes Receivable	$ 2.9		$ 2.9